King County Washington Residential Remodel and Addition Permit Guide
Unincorporated King County residential remodels, additions, deck work, garages, and many shed projects are handled through King County Permits and MyBuildingPermit.com.
Residential Remodel and Addition Permits
King County, Washington
April 26, 2026
Permit takeaway
King County processes residential additions and remodels for property in unincorporated King County; properties inside city limits must use the city's own permit process.
Zoning and placement
Before applying, confirm whether the property is in unincorporated King County and whether shoreline, critical area, fire access, septic, or land-use review applies.
Building and trade review
The residential remodel, structure addition, and repair permit type can include interior remodels, attached additions, detached accessory buildings, and repairs depending on scope.
Call before applying when
Call before applying if the property may be inside a city, the project adds floor area, affects a critical area or shoreline, includes fire access questions, or changes a detached structure.
Documents to prepare
- MyBuildingPermit.com application
- Project scope
- Site plan
- Construction drawings
- Critical area or shoreline information if applicable
Inspection planning
- Apply online
- Respond to screening or review comments
- Pay required fees
- Download approved permit documents
- Schedule inspections through MyBuildingPermit.com
Official sources
- King County Residential Addition/Remodel Service Detail
- King County Residential Permit Information
- King County Building and Land Use Permits
This guide is a planning summary. Always verify the current requirements with the local office before starting work.